BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The present invention relates to a receiver, receiving method, program and receiving
system, and more particularly, to a receiver, receiving method, program and receiving
system whose circuit scale can be reduced.
2. Description of the Related Art
[0002] Recent years have seen the use of a modulation scheme called orthogonal frequency
division multiplexing (OFDM) for transmitting digital signals. This OFDM is a digital
modulation scheme that uses a number of subcarriers orthogonal to each other in a
transmission band. Data is assigned to the amplitude and phase of each of the subcarriers.
Digital modulation is accomplished by phase shift keying (PSK) or quadrature amplitude
modulation (QAM).
[0003] The OFDM scheme is often used for terrestrial digital broadcasting that is severely
affected by multipath interference. Among terrestrial digital broadcasting standards
using OFDM are DVB-T (Digital Video Broadcasting-Terrestrial) and ISDB-T (Integrated
Services Digital Broadcasting-Terrestrial).
[0004] Incidentally, DVB-T2 (second generation European terrestrial digital broadcasting
standard) is on its way to being developed as a terrestrial digital broadcasting standard
using OFDM.
[0005] It should be noted that DVB-T2 is described in the so-called Blue Book (DVB BlueBook
A122) ("Frame structure channel coding and modulation for a second generation digital
terrestrial television broadcasting system (DVB-T2)", DVB Document A122 June 2008).
[0006] In DVB-T2 (the Blue Book thereof), a frame called a T2 frame is defined so that data
is transmitted in units of a T2 frame. A T2 frame contains two preamble signals called
P1 and P2. These preamble signals contain information required for processes such
as demodulation of an OFDM signal.
[0007] In DVB-T2, on the other hand, a scheme called M-PLP (Multiple PLP (Physical Layer
Pipes)) is used. With M-PLP, data is transmitted using two types of packet sequences.
One of them is a plurality of packet sequences (data packet sequences) called data
PLPs. The other is a packet sequence (common packet sequence) called a common PLP.
A data PLP includes a packet remaining after a packet (information) common to all
of a plurality of original transport streams (each of which will be hereinafter referred
to as a TS) has been extracted. A common packet sequence includes a common packet.
In other words, a common packet includes a packet common to a plurality of TSs, whereas
a data PLP includes a packet specific to one of the plurality of TSs. On the receiving
side, an original TS is reconstructed from common and data PLPs.
[0008] That is, a data PLP is an individual piece of service information, and a common PLP
is a common piece of information extracted from two or more data PLPs. Therefore,
the relationship data PLP count ≥ 2 × common PLP count ≥ 0 holds. As a result, there
is a multiple-to-one relationship between data PLPs and common PLP. For a given common
PLP, there are two or more data PLPs. For a given data PLP, there is a common PLP.
[0009] Fig. 1 is a diagram illustrating a T2 frame configuration.
[0010] When the transmitting side transmits a T2 frame which includes a common PLP, data
PLP#1, data PLP#2 and so on with the common PLP being a piece of information common
to a plurality of data PLPs, the receiving side proceeds as follows when receiving
this T2 frame. That is, if the data PLP#2 is specified, the receiving side selects
the data PLP#2 and the common PLP accompanying the data PLP#2 so that the original
information can decoded from these selected PLPs.
[0011] At the time of decoding, these two PLPs, i.e., the common PLP and data PLP, have
to be decoded at the same time. Further, DVB-T2 performs time interleaving to enhance
instantaneous noise immunity in the time direction. Time interleaving randomizes data
in the time direction.
[0012] A time deinterleaver used in DVB-T2 can start its output while at the same time time-deinterleaving
the time-interleaved PLP when the input of a predetermined unit of data to be processed
is complete. In this time deinterleaver, therefore, the input and output timings are
not in a one-to-one correspondence with each other.
[0013] An error correction section is provided at the succeeding stage of the time deinterleaver.
The error correction section performs error correction on the data that has been sorted
by the time deinterleaver.
[0014] If two time deinterleavers are provided, one for the common PLP and another for the
data PLP, two configurations are possible as illustrated in Figs. 2A and 2B, one in
which two error correction sections are provided, one for each PLP (Fig. 2A) and another
in which one error correction section is provided (Fig. 2B) so that it is shared by
the two PLPs. Commonly, the configuration shown in Fig. 2B is used in which a single
error correction section is shared by the two PLPs for reduced circuit scale and reduced
power consumption. Therefore, a description will be given below of a case in which
a single error correction section is shared by the two PLPs.
[0015] In Fig. 2B, each of the time deinterleavers performs time deinterleaving in units
of information to be processed called a TI-block (Time Interleaving block). These
time deinterleavers output data to the common error correction section in units of
information to be output called an FEC block. The relationship between these units
of information to be processed is as shown in Figs. 3A and 3B.
[0016] As illustrated in Figs. 3A and 3B, one TI-block corresponds to a plurality of FEC
blocks. However, when the number of TI-blocks in an interleaving frame is denoted
by NTI, this NTI may vary. That is, when NTI = 1 as illustrated in Fig. 3A, the interleaving
frame is equal to the TI-block. On the other hand, when NTI = 3 (NTI > 1) as illustrated
in Fig. 3B, the interleaving frame contains three TI-blocks. Therefore, the interleaving
frame is not equal to the TI-block.
[0017] In the case of NTI = 1 shown in Fig. 3A, each of the time deinterleavers sorts data
in the input PLP (common or data PLP) in units of a TI-block as illustrated in Fig.
4. When NTI = 1, the interleaving frame is equal to the TI-block. Each of the time
deinterleavers receives a PLP in units of a TI-block. When the input of the TI-block
data is complete, each of the time deinterleavers begins its output while at the same
time time-deinterleaving the time-interleaved PLP so that the sorted data is output
to the common error correction section.
[0018] On the other hand, when NTI = 3 (NTI > 1) as illustrated in Fig. 3B, the interleaving
frame is not equal to the TI-block. Therefore, data is sorted in units of each of
three TI-blocks or TI-block0, TI-block 1 and TI-block2, for a single interleaving
frame as illustrated in Fig. 5. However, a memory area available with the time deinterleaver
is large enough only for a single TI-block. As a result, as soon as the input of the
first TI-block or TI-block0 is complete, the time deinterleaver has to initiate its
output. Otherwise, the memory storing the TI-block0 is overwritten by the next TI-block
or TI-bIock1.
[0019] In particular, if, while one time deinterleaver outputs a PLP, the other time deinterleaver
completes its input of the first TI-block or TI-block0 among the TI-blocks where NTI
> 1, the other time deinterleaver may not initiate its output because the one time
deinterleaver is outputting its data to the common error correction section. This
causes the stored TI-block0 to be overwritten, resulting in data loss. A DVB-T2 receiver
with the features of the preamble of claim 1 is described in
DVB ORGANIZATION: "en_302769v010101rev9.doc", DVB, DIGITAL VIDEO BROADCASTING, C/O
EBU - 17A ANCIENNE ROUTE - CH-1218 GRAND SACONNEX, GENEVA- SWITZERLAND, 16 March 2009
(2009-03-16), XP017826148, * Annex C.1.1 *.
SUMMARY OF THE INVENTION
[0020] As described above, if a single error correction section is shared by the outputs
of two time deinterleavers, and if, while one time deinterleaver supplies its output
to the error correction section, the other time deinterleaver completes its input
of a predetermined unit of data to be processed, data loss will take place unless
priority is given to the output of the other time deinterleaver.
[0021] The present invention has been made in light of the foregoing problem, and it is
an aim of the present invention to prevent loss of data output from time deinterleavers
to an error correction section so as to allow for sharing of the error correction
section by the outputs of the time deinterleavers for reduced circuit scale.
[0022] A DVB-T2 receiver according to the present invention is defined in claim 1. Advantageous
features are defined in the dependent claims.
[0023] A receiving method according to the present invention is defined in claim 8. Advantageous
features are defined in the dependent claims. A program according to the present invention
is defined in claim 15. As described above, the present invention contributes to reduced
circuit scale.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024]
Fig. 1 is a diagram illustrating a T2 frame configuration;
Figs. 2A and 2B are diagrams describing configurations of a time deinterleaver and
error correction section;
Figs. 3A and 3B are diagrams describing units of information to be processed;
Fig. 4 is a diagram illustrating the output of the time deinterleaver (NTI = 1);
Fig. 5 is a diagram illustrating the output of the time deinterleaver (NTI > 1);
Fig. 6 is a diagram illustrating an embodiment of a receiver to which the present
invention is applied;
Fig. 7 is a diagram illustrating a detailed configuration of a sorting block;
Fig. 8 is a flowchart describing time deinterleaving (first case);
Fig. 9 is a timing diagram describing output interrupt;
Fig. 10 is a timing diagram describing output reversing during re-readout;
Fig. 11 is a flowchart describing time deinterleaving (second case);
Fig. 12 is a diagram illustrating a configuration example of a first embodiment of
a receiving system to which the present invention is applied;
Fig. 13 is a diagram illustrating a configuration example of a second embodiment of
the receiving system to which the present invention is applied;
Fig. 14 is a diagram illustrating a configuration example of a third embodiment of
the receiving system to which the present invention is applied; and
Fig. 15 is a diagram illustrating a configuration example of computer hardware.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] A description will be given below of embodiments of the present invention with reference
to the accompanying drawings.
[Configuration Example of the Receiver]
[0026] Fig. 6 is a diagram illustrating an embodiment of a receiver to which the present
invention is applied.
[0027] A receiver 1 shown in Fig. 6 receives a digital broadcasting signal from a transmitter
2. This signal is an OFDM signal obtained by subjecting PLPs, generated from TSs to
the processes such as error correction and OFDM modulation by means of M-PLP. M-PLP
is a scheme used in the DVB-T2 standard which is being developed as the next generation
of a terrestrial digital broadcasting standard.
[0028] That is, the transmitter 2 used, for example, in a broadcasting station, transmits
a digital broadcasting OFDM signal over a transmission line. The receiver 1 receives
an OFDM signal from the transmitter 2, decodes the signal and outputs the decoded
data obtained from decoding to the device at the subsequent stage. Decoding includes
demodulation and error correction.
[0029] In the example shown in Fig. 6, the receiver 1 includes an antenna 11, acquisition
section 12, demodulation process unit 13, decoder 14 and output section 15.
[0030] The antenna 11 receives an OFDM signal from the transmitter 2 over a transmission
line, supplying the signal to the acquisition section 12.
[0031] The acquisition section 12 includes, for example, a tuner or set-top box (STB). The
same section 12 frequency-converts the OFDM signal (RF signal) received by the antenna
11 to an IF (Intermediate Frequency) signal, supplying the resultant signal to the
demodulation process unit 13.
[0032] The demodulation process unit 13 reconstructs a TS from the PLP obtained by subjecting
the OFDM signal from the acquisition section 12 to necessary processes such as demodulation
and error correction, supplying the TS to the decoder 14.
[0033] That is, the demodulation process unit 13 includes a demodulation section 21, sorting
block 22, error correction section 23 and output interface (I/F) 24.
[0034] The demodulation section 21 demodulates the OFDM signal supplied from the acquisition
section 12, supplying the demodulated signal obtained from the demodulation to the
sorting block 22.
[0035] The sorting block 22 extracts the specified data PLP and the common PLP associated
therewith from the demodulated signal supplied from the demodulation section 21 and
subjects the PLPs to predetermined sorting, supplying the PLPs to the error correction
section 23.
[0036] The error correction section 23 subjects the PLP (data or common PLP), which is supplied
from the sorting block 22 and has undergone the sorting, to a predetermined error
correction, outputting the resultant PLP to the output I/F 24.
[0037] Here, the transmitter 2 transmits, for example as an OFDM signal, PLPs that are generated
from TSs. These TSs are made up of TS packets containing MPEG (Moving Picture Experts
Group)-coded data. This MPEG-coded data is produced by MPEG-coding video and audio
data as a program.
[0038] Further, the transmitter 2 codes PLPs, for example, into RS (Reed Solomon) or LDPC
(Low Density Parity Check) codes as a countermeasure against errors that may take
place on a transmission line. Therefore, the error correction section 23 decodes these
codes as an error correction coding process.
[0039] The output I/F 24 reconstructs the TS from the PLP supplied from the error correction
section 23, outputting the reconstructed TS to external equipment at a predetermined
rate.
[0040] The decoder 14 MPEG-decodes the MPEG-coded data contained in the TS supplied from
the output I/F 24, supplying the video and audio data, obtained from the MPEG decoding,
to the output section 15.
[0041] The output section 15 includes, for example, a display and speaker and displays an
image and produces a sound in accordance with the video and audio data supplied from
the decoder.
[0042] The receiver 1 is configured as described above.
[Configuration Example of the Sorting Block]
[0043] Fig. 7 is a diagram illustrating a detailed configuration of the sorting block 22
shown in Fig. 6.
[0044] In Fig. 7, a data structure is shown under each of the blocks to describe the details
of the process performed in the associated block. These data structures will be referred
to as appropriate for the description of the processes.
[0045] As illustrated in Fig. 7, the sorting block 22 includes a frequency deinterleaver
31, PLP extraction part 32, time deinterleaver 33 and FEC deinterleaver 34.
[0046] The demodulation performed by the demodulation section 21 is performed in units of
a T2 frame as described above. This T2 frame contains a P1 symbol (not shown), P2
symbol and data symbol in this order. The two types of preambles called P1 and P2
contain information required for demodulation of the OFDM signal and other processes.
[0047] A P1 symbol is designed to transmit P1 signalling. On the other hand, a P2 symbol
is designed to transmit L1 pre-signalling and L1 post-signalling.
[0048] L1 pre-signalling contains information required for a receiver adapted to receive
a T2 frame to receive and decode L1 post-signalling. L1 post-signalling contains parameters
required for a receiver to access the physical layer (or its pipes). Further, L1 post-signalling
contains information required to decode common and data PLPs (hereinafter referred
to as PLP information). That is, if PLP information on common and data PLPs associated
with an intended service is detected from L1 post-signalling, the data and common
PLPs in the data symbol associated with the detected PLP information are selected
and decoded.
[0049] That is, first of all, the demodulation section 21 adapted to demodulate an OFDM
signal used in DVB-T2 proceeds, for example, with the demodulation of P1 signalling
in the T2 frame, in which P1 has been detected, during a so-called channel line scan.
Then, the demodulation section 21 performs predetermined calculations related to P2.
When it becomes possible to demodulate L1 pre-signalling contained in P2, data can
be demodulated from this point in time onward. The demodulated signal obtained from
this demodulation is supplied to the sorting block 22.
[0050] In the sorting block 22, the frequency deinterleaver 31 performs frequency deinterleaving
by sorting data of the demodulated signal supplied from the demodulation section 21
in the frequency domain according to a predetermined rule using an unshown memory
as a work area. The demodulated signal whose data has been sorted within the symbol
by this frequency deinterleaving is supplied to the PLP extraction part 32.
[0051] The PLP extraction part 32 extracts the specified data PLP and the common PLP associated
therewith from the demodulated signal supplied from the frequency deinterleaver 31
based on the PLP information detected by the demodulation section 21, supplying the
extracted data to the time deinterleaver 33.
[0052] The time deinterleaver 33 includes a time deinterleaver 33A, time deinterleaver 33B,
control part 51 and memory 52.
[0053] The time deinterleaver 33A performs time deinterleaving by sorting the data of the
common PLP extracted from the PLP extraction part 32 in the time domain according
to a predetermined rule using the memory 52 such as a RAM (Random Access Memory) as
a work area. The common PLP that has undergone time deinterleaving is supplied to
the FEC deinterleaver 34.
[0054] The time deinterleaver 33B performs time deinterleaving by sorting the data of the
data PLP extracted from the PLP extraction part 32 in the time domain according to
a predetermined rule using the memory 52 as a work area as does the time deinterleaver
33A. The processing result is supplied to the FEC deinterleaver 34.
[0055] The control part 51 controls the time deinterleavers 33A and 33B to perform time
deinterleaving. It should be noted that a RAM 51A is provided in the control part
51 so that information required for time deinterleaving is stored as appropriate.
[0056] As the control part 51 controls the time deinterleavers 33A and 33B associated with
the respective PLPs, the time deinterleaver 33A starts its output while at the same
time time-deinterleaving the time-interleaved common PLP when the input of a predetermined
TI-block of the common PLP, which is supplied in units of a TI-block, is complete.
Similarly, the time deinterleaver 33B starts its output while at the same time time-deinterleaving
the time-interleaved data PLP when the input of a predetermined TI-block of the data
PLP, which is supplied in units of a TI-block, is complete.
[0057] The control part 51 switches the output of the time deinterleaver 33A over to that
of the time deinterleaver 33B under the following condition. That is, the control
part 51 switches the output if, while the time deinterleaver 33A supplies its output,
the time deinterleaver 33B completes its writing of the first TI-block to the memory
52 when there are NTI (where NTI > 1) TI-blocks in the data PLP of the time deinterleaver
33B. At this time, the control part 51 stores, for example, information indicating
the amount of the PLP remaining to be output as information required to resume the
output of the time deinterleaver 33A (hereinafter referred to as resumption information)
that was discontinued halfway.
[0058] The control part 51 permits the time deinterleaver 33B to output the TI-blocks with
priority until the output of the (NTI-1) or NTI TI-blocks is complete. Thereafter,
when the output of the (NTI-1) or NTI TI-blocks is complete, the control part 51 switches
the output of the time deinterleaver 33B that has been outputting the TI-blocks with
priority over to that of the time deinterleaver 33A that was discontinued halfway.
Then, the control part 51 allows for the time deinterleaver 33A to resume the readout
of the common PLP that was discontinued previously.
[0059] Thanks to the output control of the control part 51, either the common or data PLP
is supplied to the FEC deinterleaver 34 in units of an FFC block.
[0060] If, contrary to the relationship described above, and while the time deinterleaver
33B supplies its output, the time deinterleaver 33A completes the writing of the first
TI-block to the memory 52 when there are NTI (where NTI > 1) TI-blocks in the common
PLP of the time deinterleaver 33A, the time deinterleavers 33A and 33B merely play
opposite roles to those described above. Therefore, the processes performed by the
time deinterleavers under the control of the control part 51 remain unchanged.
[0061] The FEC deinterleaver 34 performs FEC deinterleaving by sorting the data of the common
or data PLP output from the time deinterleaver 33 in units of an FEC block according
to a predetermined rule using an unshown memory as a work area. The common or data
PLP whose data has been sorted in the FEC block is supplied to the error correction
section 23.
[0062] The error correction section 23 is supplied with the common or data PLP signal in
units of an FEC block from the time deinterleaver 33 via the FEC deinterleaver 34
under the output control of the control part 51. The error correction section 23 is
shared by the common and data PLPs. Depending on which of the common and data PLPs
is input, the same section 23 performs error correction on the common or data PLP.
[Description of the Time Deinterleaving]
[0063] Fig. 8 is a flowchart describing time deinterleaving (first case) performed by the
time deinterleaver 33.
[0064] In the description of Fig. 8, the expressions "one PLP" and "other PLP" are intended
to mean that both common and data PLPs are acceptable.
[0065] That is, when the common PLP is "one PLP," the data PLP is "other PLP." In this case,
the time deinterleaver 33A, i.e., one time deinterleaver, performs time deinterleaving
on the common PLP, i.e., one PLP, and the time deinterleaver 33B, i.e., other time
deinterleaver, performs time deinterleaving on the data PLP, i.e., other PLP. In contrast,
when the data PLP is "one PLP", the common PLP is "other PLP." In this case, the time
deinterleaver 33B, i.e., one time deinterleaver, performs time deinterleaving on the
data PLP, i.e., one PLP, and the time deinterleaver 33A, i.e., other time deinterleaver,
performs time deinterleaving on the common PLP, i.e., other PLP.
[0066] In step S11, the control part 51 causes the time deinterleaver to write a common
or data PLP, which has been input following OFDM demodulation, to the memory 52. In
step S12, the control part 51 determines whether the writing of the common or data
PLP to the memory 52 is complete.
[0067] In step S12, if the control part 51 determines that the writing to the memory 52
is not complete, the process returns to step S11 where the control part 51 repeats
its determination in step S12 until the writing of one PLP is complete.
[0068] On the other hand, when the control part 51 determines that the writing of one PLP
is complete in step S12, the one time deinterleaver 33 performs time deinterleaving
by sorting the data of the one PLP that has been written to the memory 52 in the time
domain according to a predetermined rule.
[0069] In step S14, the control part 51 determines whether the output of the one PLP is
complete. When the control part 51 determines that the output of the one PLP is complete,
the process proceeds to step S26 where the control part 51 determines whether a next
PLP has been input.
[0070] On the other hand, if the control part 51 determines in step S14 that the output
of the one PLP is not complete, the control part 51 determines in step S15 whether
NTI is greater than 1 for the other PLP. When the control part 51 determines in step
S15 that NTI is greater than 1 for the other PLP, the same section 51 determines in
step S16 whether the writing of the first TI-block of the other PLP with NTI greater
than 1 to the memory 52 is complete.
[0071] If the control part 51 determines that NTI is not greater than 1 in the other PLP
(No in step S15), or if the same section 51 determines that the writing of the first
TI-block of the other PLP is not complete (No in step S16), the output of the one
PLP continues. Therefore, the process returns to step S13 where the output of the
one PLP is repeated.
[0072] On the other hand, when the control part 51 determines in step S16 that the writing
of the first TI-block of the other PLP is complete, the same section 51 stores resumption
information such as the amount of the PLP remaining to be output in the RAM 51A and
switches the PLP to be output to the error correction section 23 from the one PLP
over to the other PLP in step S18.
[0073] In step S19, the other time deinterleaver 33 performs time deinterleaving by sorting
the data of the other PLP that has been written to the memory 52 in the time domain
according to a predetermined rule.
[0074] The control part 51 determines in step S20 whether the output of the NTI-1 TI-blocks
is complete as a result of the time deinterleaving on the other PLP. If the control
part 51 determines that the output of the NTI-1 TI-blocks is not complete, the process
returns to step S19 where the output of the one PLP is repeated.
[0075] On the other hand, when the control part 51 determines in step S20 that the output
of the NTI-1 TI-blocks is complete, the same section 51 switches the PLP to be output
from the other PLP over to the one PLP in step S21. Then, the control part 51 reads
out the resumption information from the RAM 51A and causes the output of the other
PLP, which was discontinued halfway, to be resumed in step S22. This allows for the
one time deinterleaver 33 to perform time deinterleaving on the remaining one PLP
and resume the output thereof.
[0076] It should be noted that, as described earlier, the time deinterleavers 33 output
the PLPs in units of an FEC block. Therefore, if the output is discontinued halfway
through an FEC block, the FEC block has to be read out from the beginning again. A
detailed description thereof will be given later with reference to Fig. 10.
[0077] The control part 51 determines in step S23 whether the output of the one PLP is complete.
If the same section 51 determines that the output of the one PLP is not complete,
the process returns to step S22 where the output of the one PLP is repeated.
[0078] On the other hand, when the control part 51 determines that the output of the one
PLP is complete, the same section 51 switches the PLP to be output again from the
one PLP over to the other PLP in step S24. Then, the other time deinterleaver 33 performs
time deinterleaving in step S25 by sorting the data of the NTI TI-blocks of the other
PLP that have been written to the memory 52 in the time domain according to a predetermined
rule.
[0079] In step S26, the control part 51 determines whether the input of a PLP is complete.
If the same section 51 determines that the input of a PLP is not complete, the process
returns to step S11 where the above-described time deinterleaving is repeated.
[0080] On the other hand, if control part 51 determines in step S26 that the input of a
PLP is complete, the time deinterleaving is terminated.
[0081] The time deinterleaving is performed as described above.
[0082] A description will be given next of the time deinterleaving described with reference
to the flowchart shown in Fig. 8 in a more detailed manner with reference to the timing
diagrams shown in Figs. 9 and 10.
[0083] Fig. 9 is a timing diagram describing output interrupt (corresponding to the process
in step S16 of Fig. 8) during time deinterleaving. It should be noted that time elapses
from left to right in Fig. 9.
[0084] As illustrated in Fig. 9, the input of a common PLP begins from time t
1. When the writing of a TI-block to the memory 52 is complete at time t
2, the time deinterleaver 33A sorts the data in the TI-block in the time domain according
to a predetermined rule and begins its output in units of an FEC block.
[0085] At time t
3 when the time deinterleaver 33A outputs the TI-block, the input of a data PLP with
NTI = 3 to the time deinterleaver 33B begins. As a result, the writing of the first
TI-block, i.e., TI-block0, is complete at time t
4. However, it has been repeatedly mentioned that, in this condition, the written TI-block0
is overwritten by the TI-block1 that is input as the second TI-block. At time t
4, for this reason, the control part 51 switches the output of the time deinterleaver
33A over to that of the time deinterleaver 33B, interrupting the output of the TI-block
of the common PLP to output the TI-block0 of the data PLP.
[0086] As a result, the time deinterleaver 33B processes the output of the TI-block0 with
priority, sorting the data of the TI-block0 in the time domain according to a predetermined
rule and outputting the TI-block0 with sorted data. On the other hand, the output
of the TI-block of the common PLP that has been interrupted is discontinued temporarily
at time t
4. However, the resumption information such as the amount of the PLP remaining to be
output is stored in the RAM 51A.
[0087] Then, while the TI-block0 is output, the TI-block1, i.e., the second TI-block, is
written to the memory 52. At time t
5, the writing of the TI-block1 is complete simultaneously with the end of the output
of the TI-block0. At this time, therefore, the output of the TI-block1 begins. Thus,
the TI-block0 and TI-block1 are output in an orderly manner, thus preventing the memory
52 from being overwritten. However, NTI = 3 in the data PLP. Therefore, the output
of the TI-block of the common PLP is resumed when the output of the second TI-block
(NTI = 3 - 1 = 2) is complete. That is, the output of the TI-block1 is complete at
time t
6. As a result, the control part 51 switches the output of the time deinterleaver 33B
over to that of the time deinterleaver 33A before initiating the output of the third
TI-block, i.e., TI-block2, resuming the output of the TI-block of the common PLP (process
in step S22 of Fig. 8).
[0088] When the output of the one PLP is resumed, the readout is resumed from the position
specified by the resumption information stored in the RAM 51A. However, the time deinterleavers
33 output the PLPs in units of an FEC block. Therefore, the one PLP has to be output
accordingly. That is, if the output is discontinued halfway through an FEC block,
resuming the readout from where the output is discontinued results in failure of a
portion of the FEC block to be output due to the interrupt.
[0089] The timing diagram of Fig. 10 shows the relationship between the output of the time
deinterleaver 33A and the FEC block when an interrupt occurs at time t
4. If the output is resumed from where the interrupt occurs, the unit of data to be
output (FEC block) is incomplete. Therefore, the control part 51 ensures that the
FEC block is read out again from the beginning rather than from halfway based on the
start flag of the FEC block during the re-readout. This allows for the complete FEC
block to be output as if the output is rewound.
[0090] Referring back to Fig. 9, when the resumed output of the TI-block of the common PLP
is complete at time t
7, the control part switches the output of the time deinterleaver 33A over to that
of the time deinterleaver 33B again, allowing the remaining TI-block2, i.e., the third
TI-block, to be read out and output (process in step S25 of Fig. 8).
[0091] As described above, if, while the output of the one PLP is in progress, the writing
of the first TI-block of the other PLP to the memory 52 is complete when there are
NTI (where NTI > 1) TI-blocks in the other PLP, the output of the one PLP is switched
over to the output of the other PLP. This prevents the first TI-block from being overwritten,
thus preventing data loss (memory failure).
[0092] As a result, the error correction section 23 can be shared by the common and data
PLPs, thus providing reduced circuit scale and reduced power consumption.
[0093] Incidentally, the first case of time deinterleaving was described as follows with
reference to the flowchart of Fig. 8. That is, if, while the output of the one PLP
is in progress, the other PLP with NTI > 1 is input, the output of the one PLP is
switched over to the output of the other PLP. Then, when the output of one of the
NTI-1 TI-blocks is complete, the output of the other PLP is switched over to the output
of the one PLP. However, the output of the other PLP may be switched over to the output
of the one PLP after the output of the NTI TI-blocks is complete.
[0094] A description will be given next of a second case of the time deinterleaving in which
the output of the other PLP is switched over to the output of the one PLP after the
output of the NTI TI-blocks is complete with reference to the flowchart shown in Fig.
11.
[0095] In steps S31 to S39 of Fig. 11, if, while the output of the one PLP is in progress,
the other PLP with NTI > 1 is input, the output of the one PLP is switched over to
the output of the other PLP, allowing time deinterleaving to be performed on the other
PLP as with steps S11 to S19 of Fig. 8.
[0096] The control part 51 determines in step S40 whether the output of the NTI-1 TI-blocks
is complete as a result of the time deinterleaving on the other PLP. If the control
part 51 determines in step S40 that the output of the NTI-1 TI-blocks is not complete,
that is, if NTI = 3, the output of three (NTI = 3) TI-blocks has yet to be complete.
Therefore, the process returns to step S39 where the output of the other PLP by the
other time deinterleaver 33 is repeated.
[0097] On the other hand, when the control part 51 determines in step S40 that the output
of the NTI-1 TI-blocks is complete, the same section 51 switches the PLP to be output
from the other PLP over to the one PLP. Then, the same section 51 reads out the resumption
information of the one PLP from the RAM 51A in step S42, resuming the output of the
one PLP that was discontinued halfway.
[0098] The control part 51 determines in step S43 whether the output of the one PLP is complete.
If the same section 51 determines that the output thereof is not complete, the process
returns to step S42 where the output of the one PLP by the one time deinterleaver
33 is repeated.
[0099] On the other hand, when the control part 51 determines in step S43 that the output
of the one PLP is complete, the same section 51 determines in step S44 whether the
input of a PLP is complete as with step S26 of Fig. 8. When the same section 51 determines
that the input of a PLP is complete, the time deinterleaving is terminated.
[0100] Thus, it is possible to prevent the overwriting of a TI-block by ensuring that a
TI-block that has yet to be output is not overwritten by the next TI-block or that
all the TI-blocks are output, as after the completion of output of NTI-1 or NTI Tl-blocks.
Further, resuming the output by determining whether the output of NTI TI-blocks is
complete ensures a smaller number of times the output is switched than resuming the
output by determining whether the output of NTI-1 TI-blocks is complete because the
former eliminates the need to switch over to the output of the other PLP after the
completion of the resumed output.
[Configuration Example of the Receiving System]
[0101] A description will be given next of the configuration of a receiving system with
reference to Figs. 12 to 14.
[0102] Fig. 12 is a diagram illustrating a configuration example of a first embodiment of
a receiving system to which the present invention is applied.
[0103] In Fig. 12, the receiving system includes an acquisition section 201, transmission
line decoding section 202 and source decoding section 203.
[0104] The acquisition section 201 acquires an OFDM signal compliant with M-PLP used in
DVB-T2 via an unshown transmission line such as terrestrial digital broadcasting,
satellite digital broadcasting, CATV (Cable Television) network, the Internet or other
network. The same section 201 supplies the OFDM signal to the transmission line decoding
section 202.
[0105] When an OFDM signal is broadcast from a broadcasting station, for example, via terrestrial
wave, satellite wave or CATV network, the acquisition section 201 includes a tuner
or STB as does the acquisition section 12 shown in Fig. 6. On the other hand, when
an OFDM signal is multicast as in IPTV (Internet Protocol Television), the acquisition
section 201 includes, for example, a network I/F such as NIC (Network Interface Card).
[0106] When an OFDM signal is broadcast from a broadcasting station, for example, via terrestrial
wave, satellite wave or CATV network, OFDM signals broadcast from a plurality of transmitters
via a plurality of transmission lines are received by the single acquisition section
201. As a result, the OFDM signals are received as a single combined OFDM signal.
[0107] The transmission line decoding section 202 subjects the OFDM signal, obtained by
the acquisition section 201 over a transmission line, to transmission line decoding
including at least PLP decoding, supplying the resultant signal to the source decoding
section 203.
[0108] That is, an OFDM signal compliant with M-PLP is defined by a plurality of data PLPs
and a common PLP. Each of the data PLPs includes a packet remaining after a packet
common to all TSs has been extracted. The common packet sequence includes a common
packet. The transmission line decoding section 202 subjects such an OFDM signal to
PLP (packet sequence) decoding.
[0109] Further, the OFDM signal obtained by the acquisition section 201 over a transmission
line is distorted under the influence of transmission line characteristics. The transmission
line decoding section 202 subjects such a signal, for example, to demodulation such
as transmission line estimation, channel estimation or phase estimation.
[0110] Still further, transmission line decoding includes a process adapted to correct errors
that take place in the transmission line. Among error correction coding processes
are LDPC coding and Reed Solomon coding.
[0111] The source decoding section 203 subjects the signal, which has undergone transmission
line decoding, to source decoding including at least a process adapted to decompress
the compressed information into the original information.
[0112] That is, the OFDM signal obtained by the acquisition section 201 over a transmission
line may be compression-coded to compress the information so as to reduce the amount
of data such as video and audio data as information. In this case, the source decoding
section 203 subjects the signal, which has undergone transmission line decoding, to
source decoding such as a process adapted to decompress the compressed information
into the original information (decompression).
[0113] It should be noted that when the OFDM signal obtained by the acquisition section
20 1 over a transmission line is not compression-coded, the source decoding section
203 does not perform the process adapted to decompress the compressed information
into the original information.
[0114] Here, MPEG decoding is an example of decompression. On the other hand, transmission
line decoding may include not only decompression but also descrambling and other processes.
[0115] In the receiving system configured as described above, the acquisition section 201
subjects video, audio and other data, for example, to compression coding such as MPEG
coding. Further, the acquisition section 201 acquires an M-PLP-compliant OFDM signal,
which has undergone error correction coding, via a transmission line, supplying the
OFDM signal to the transmission line decoding section 202. It should be noted that
the OFDM signal is, at this time, distorted under the influence of transmission line
characteristics.
[0116] The transmission line decoding section 202 subjects the OFDM signal supplied from
the acquisition section 201 to the same processes as used by the demodulation process
unit 13 shown in Fig. 6 as transmission line coding. The same section 202 supplies
the resultant signal to the source decoding section 203.
[0117] The source decoding section 203 subjects the signal supplied from the transmission
line decoding section 202 to the same processes as used by the decoder 14 shown in
Fig. 6 as source decoding. The source decoding section 203 outputs the resultant image
or sound.
[0118] The receiving system shown in Fig. 12 configured as described above is applicable,
for example, to a television tuner adapted to receive digital television broadcasting.
[0119] The acquisition section 201, transmission line decoding section 202 and source decoding
section 203 can each be configured as a single independent device (hardware (e.g.,
IC (Integrated Circuit)) or a software module.
[0120] Further, the acquisition section 201 and transmission line decoding section 202 may
be combined as a single independent device. Alternatively, the transmission line decoding
section 202 and source decoding section 203, or the all three sections, may be combined
as a single independent device.
[0121] Fig. 13 is a diagram illustrating a configuration example of a second embodiment
of the receiving system to which the present invention is applied.
[0122] It should be noted that like components to those in Fig. 12 are denoted by the same
reference numerals, and the description thereof will be omitted below.
[0123] The receiving system shown in Fig. 13 is identical to the receiving system shown
in Fig. 12 in that it includes the acquisition section 201, transmission line decoding
section 202 and source decoding section 203, but differs therefrom in that it additionally
includes an output section 211.
[0124] The output section 211 is, for example, a display device adapted to display an image
or a speaker adapted to produce a sound. The same section 211 outputs, for example,
an image or sound that is output in the form of a signal from the source decoding
section 203. That is, the output section 211 displays an image or produces a sound.
[0125] The receiving system shown in Fig. 13 configured as described above is applicable,
for example, to a television receiver adapted to receive digital television broadcasting
or radio receiver adapted to receive radio broadcasting.
[0126] It should be noted that if the OFDM signal obtained by the acquisition section 201
is not compression-coded, the output signal from the transmission line decoding section
202 is supplied to the output section 211.
[0127] Fig. 14 is a diagram illustrating a configuration example of a third embodiment of
the receiving system to which the present invention is applied.
[0128] It should be noted that like components to those in Fig. 12 are denoted by the same
reference numerals, and the description thereof will be omitted below.
[0129] The receiving system shown in Fig. 14 is identical to the receiving system shown
in Fig. 12 in that it includes the acquisition section 201 and transmission line decoding
section 202.
[0130] However, the receiving system shown in Fig. 14 differs therefrom in that it does
not include the source decoding section 203, but additionally includes a recording
section 221.
[0131] The recording section 221 records (stores) a signal (e.g., MPEG TS packet) output
from the transmission line decoding section 202 on a recording (storage) medium such
as optical disk, harddisk (magnetic disk), or flash memory.
[0132] The receiving system configured as described above is applicable, for example, to
a recorder adapted to record television broadcasting.
[0133] It should be noted that the receiving system shown in Fig. 14 may include the source
decoding section 203 so that the signal source-decoded by the same section 203, i.e.,
an image or sound obtained by decoding, can be recorded by the recording section 221.
[Description of the Computer to Which the Present Invention is Applied]
[0134] Incidentally, the above series of processes may be performed by hardware or software.
If the series of processes are performed by software, the program making up the software
is installed to a computer. Here, such a computer may be incorporated in dedicated
hardware. Alternatively, such a computer may be able to perform a variety of functions
when installed with a variety of programs.
[0135] Fig. 15 is a diagram illustrating a configuration example of computer hardware which
performs the above series of processes by the program.
[0136] In the computer, a CPU (Central Processing Unit) 401, ROM (Read Only Memory) 402
and RAM (Random Access Memory) 403 are connected together via a bus 404.
[0137] Further, an I/O interface 405 is connected to the bus 404. An input section 406,
output section 407, storage section 408, communication section 409 and drive 410 are
connected to the I/O interface 405.
[0138] The input section 406 includes, for example, a keyboard, mouse and microphone. The
output section 407 includes, for example, a display and speaker. The storage section
408 includes, for example, a hard disk or nonvolatile memory. The communication section
409 includes, for example, a network interface. The drive 410 drives, for example,
a removable medium 411 such as magnetic disk, optical disk, magneto-optical disk or
semiconductor memory.
[0139] In the computer configured as described above, the CPU 401 loads the program from
the storage section 408 via the I/O interface 405 and bus 404 into execution, thus
allowing for the above series of processes to be performed.
[0140] The program executed by the computer (CPU 401) can be supplied, recorded on the removable
medium 411 such as a package medium. Alternatively, the program can be supplied via
a wired or wireless transmission medium such as local area network, the Internet or
digital broadcasting.
[0141] In the computer, the program can be installed to the storage section 408 via the
I/O interface 405 by inserting the removable medium 411 into the drive 410. Alternatively,
the program can be installed to the storage section 408 by receiving the program with
the communication section 409 via a wired or wireless transmission medium. Still alternatively,
the program may be preinstalled in the ROM 402 or storage section 408.
[0142] In the present specification, the steps describing the program stored in the recording
medium include not only the processes performed chronologically according to the described
sequence but also those that are not performed necessarily chronologically but are
performed in parallel or separately.
[0143] On the other hand, the term "system" refers in the present specification to an apparatus
as a whole that is made up of a plurality of devices.
1. A DVB-T2 receiver (1) comprising:
receiving means (11) for receiving an Orthogonal Frequency Division Multiplexing signal
obtained by modulating a common packet sequence and data packet sequence, the common
packet sequence being made up of packets common to a plurality of streams, and the
data packet sequence being made up of packets specific to one of the plurality of
streams the plurality of streams being Physical Layer Pipes, PLPs, and the common
packet sequence being a common PLP and the data packet sequence being a data PLP,
error correction means (23) and
a time deinterleaver (33) which comprises:
a first time deinterleaver (33A) for sorting the common packet sequence, obtained
by demodulating the received Orthogonal Frequency Division Multiplexing signal, in
the time domain; and
a second time deinterleaver (33B) for sorting the data packet sequence, obtained by
demodulating the received Orthogonal Frequency Division Multiplexing signal, in the
time domain;
a memory (52);
a control part (51) for switching the output to the error correction means (23) for
handling
error correction from the first time deinterleaver (33A) over to second time deinterleaver
(33B) if, while the first time deinterleaver (33A) supplies its output to the error
correction means (23), the second time deinterleaver (33B) completes its writing of
a predetermined unit of information to be processed to the memory (52) and for storing
information required to resume the output of the first time deinterleaver (33A).
2. The DVB-T2 receiver (1) of claim 1, wherein
the control part (51) switches the output from the first time deinterleaver (33A)
over to the second time deinterleaver (33B) when the input of the first predetermined
unit of information to be processed is complete if there are two or more predetermined
units of information to be processed of a predetermined frame in the other sorting
means.
3. The DVB-T2 receiver (1) of claim 1 or 2, wherein
the control part (51) switches the output to the error correction means from the second
time deinterleaver (33B) over to the first time deinterleaver (33A) when the output
of the predetermined unit of information processed from the second time deinterleaver
(33B) is complete.
4. The DVB-T2 receiver (1) of claim 1, 2 or 3 wherein:
said control part (51) is further adapted to control the output of the first time
deinterleaver (33A) so that the output from the first time deinterleaver (33A), to
which the output has been switched over, resumes from the beginning of the predetermined
unit that was terminated incompletely.
5. The DVB-T2 receiver (1) of claim 4, wherein
the control part (51) switches the output from the second time deinterleaver (33B)
over to the first time deinterleaver (33A) when there is one predetermined unit of
information to be processed left in the second time deinterleaver (33B) if there are
two or more predetermined units of information to be processed of a predetermined
frame in the second time deinterleaver (33B), and
then, the control part (51) switches the output again from the first time deinterleaver
(33A) over to the second time deinterleaver (33B) after the resumed output of information
by the first time deinterleaver (33A) is complete.
6. The DVB-T2 receiver (1) of claim 4, wherein
the control part (51) switches the output from the second time deinterleaver (33B)
over to the first time deinterleaver (33A) when the output of all the units of information
processed from the second time deinterleaver (33B) is complete if there are two or
more predetermined units of information processed of a predetermined frame in the
second time deinterleaver (33B).
7. The DVB-T2 receiver (1) of one of the claims 1 to 6 further comprising:
error correction means (23) for performing error correction on the output of either
the first or second time deinterleaver (33A or 33B).
8. A receiving method for a DVB-T2 receiver (1), the DVB-T2 receiver (1) having receiving
means (11), first and second time deinterleavers (33A and 33B), a control part (51),
error correction means (23) and a memory (52), the receiving method comprising the
steps of:
Receiving, by the receiving means (11), an Orthogonal Frequency Division Multiplexing
signal obtained by modulating a common packet sequence and data packet sequence, the
common packet sequence being made up of packets common to a plurality of streams,
and the data packet sequence being made up of packets specific to one of the plurality
of streams the plurality of streams being Physical Layer Pipes, PLPs, and the common
packet sequence being a common PLP and the data packet sequence being a data PLP;
Sorting, by the first time deinterleaver (33A), the common packet sequence, obtained
by demodulating the received Orthogonal Frequency Division Multiplexing signal, in
the time domain; and
Sorting, by the second time deinterleaver (33B), the data packet sequence, obtained
by demodulating the received Orthogonal Frequency Division Multiplexing signal, in
the time domain;
Switching, by the control part (51), the output to the error correction means (23)
for handling error correction from the first time deinterleaver (33A) over to the
second time deinterleaver (33B) if, while the first time deinterleaver (33A) supplies
its output to the error correction means (23), the second time deinterleaver (33B)
completes its writing of a predetermined unit of information to be processed to the
memory (52) and storing information required to resume the output of the first time
deinterleaver (33A).
9. The receiving method according to claim 8, further comprising:
Switching, by the control part (51), the output from the first time deinterleaver
(33A) over to the second time deinterleaver (33B) when the input of the first predetermined
unit of information to be processed is complete if there are two or more predetermined
units of information to be processed of a predetermined frame in the other sorting
means.
10. The receiving method according to claim 8 or 9, further comprising:
Switching, by the control part (51), the output to the error correction means from
the second time deinterleaver (33B) over to the first time deinterleaver (33A) when
the output of the predetermined unit of information processed from the second time
deinterleaver (33B) is complete.
11. The receiving method according to any of claims 8, 9 or 10, further comprising:
Controlling, by said control part (51), the output of the first time deinterleaver
(33A) so that the output from the first time deinterleaver (33A), to which the output
has been switched over, resumes from the beginning of the predetermined unit that
was terminated incompletely.
12. The receiving method according to claim 11 further comprising:
Switching, by the control part (51), the output from the second time deinterleaver
(33B) over to the first time deinterleaver (33A) when there is one predetermined unit
of information to be processed left in the second time deinterleaver (33B) if there
are two or more predetermined units of information to be processed of a predetermined
frame in the second time deinterleaver (33B), and
then, switching, by the control part (51), the output again from the first time deinterleaver
(33A) over to the second time deinterleaver (33B) after the resumed output of information
by the first time deinterleaver (33A) is complete.
13. The receiving method according to claim 11, further comprising:
Switching, by the control part (51), the output from the second time deinterleaver
(33B) over to the first time deinterleaver (33A) when the output of all the units
of information processed from the second time deinterleaver (33B) is complete if there
are two or more predetermined units of information processed of a predetermined frame
in the second time deinterleaver (33B).
14. The receiving method according to any of claims 8 - 13, further comprising:
Performing error correction, by the error correction means (23), on the output of
either the first or second time deinterleaver (33A or 33B).
15. A program for a computer, which, when loaded into the computer, is adapted to perform
the steps of the receiving method of any of claims claim 8 - 14.
1. DVB-T2-Empfänger (1), umfassend:
Empfangsmittel (11) zum Empfangen eines orthogonalen Frequenzmultiplex-Signals, das
durch Modulieren einer gemeinsamen Paketfolge und einer Datenpaketfolge erhalten wird,
wobei die gemeinsame Paketfolge aus Paketen besteht, die einer Vielzahl von Strömen
gemeinsam sind, und wobei die Datenpaketfolge aus Paketen besteht, die für eines der
Vielzahl von Strömen spezifisch sind, wobei die Vielzahl von Strömen Physical Layer
Pipes (PLPs) und die gemeinsame Paketfolge ein gemeinsames PLP und die Datenpaketfolge
ein Daten-PLP, Fehlerkorrekturmittel (23) und ein Zeitentschachteler (33)ist, die
Folgendes umfassen:
einen ersten Zeitentschachteler (33A) zum Sortieren der gemeinsamen Paketfolge, die
durch Demodulieren des empfangenen orthogonalen Frequenzmultiplexsignals im Zeitbereich
erhalten wird; und
einen zweiten Zeitentschachteler (33B) zum Sortieren der Datenpaketfolge, die durch
Demodulieren des empfangenen orthogonalen Frequenzmultiplexsignals im Zeitbereich
erhalten wird;
einen Speicher (52);
einen Steuerungsteil (51) zum Umschalten der Ausgabe an die Fehlerkorrekturmittel
(23) zum Behandeln der Fehlerkorrektur vom ersten Zeitentschachteler (33A) bis zum
zweiten Zeitentschachteler (33B), wenn, während der erste Zeitentschachteler (33A)
seine Ausgabe an die Fehlerkorrekturmittel (23) liefert, der zweite Zeitentschachteler
(33B) sein Schreiben einer vorbestimmten Informationseinheit beendet, die in den Speicher
(52) zu verarbeiten ist, und Informationen speichert, die erforderlich sind, um die
Ausgabe des ersten Zeitentschachtelers (33A) fortzusetzen.
2. DVB-T2-Empfänger (1) nach Anspruch 1, worin der Steuerungsteil (51) die Ausgabe vom
ersten Zeitentschachteler (33A) auf den zweiten Zeitentschachteler (33B) umschaltet,
wenn die Eingabe der ersten vorbestimmten Informationseinheit, die zu verarbeiten
ist, vollständig ist, wenn zwei oder mehrere vorbestimmte Informationseinheiten vorhanden
sind, die von einem vorbestimmten Rahmen in den anderen Sortiermitteln zu verarbeiten
sind.
3. DVB-T2-Empfänger (1) nach Anspruch 1 oder 2, worin der Steuerungsteil (51) die Ausgabe
vom zweiten Zeitentschachteler (33B) auf das Fehlerkorrekturmittel zum ersten Zeitentschachteler
(33A) schaltet, wenn die Ausgabe der vorbestimmten Informationseinheit, die vom zweiten
Zeitentschachteler (33B) verarbeitet wird, abgeschlossen ist.
4. DVB-T2-Empfänger (1) nach Anspruch 1, 2 oder 3, worin:
der Steuerungsteil (51) ferner angepasst ist, um die Ausgabe des ersten Zeitentschachtelers
(33A) so zu steuern, dass die Ausgabe vom ersten Zeitentschachteler (33A), auf den
die Ausgabe umgeschaltet wurde, vom Beginn der vorbestimmten Einheit, die unvollständig
beendet wurde, wieder aufgenommen wird.
5. DVB-T2-Empfänger (1) nach Anspruch 4, worin der Steuerungsteil (51) die Ausgabe vom
zweiten Zeitentschachteler (33B) auf den ersten Zeitentschachteler (33A) umschaltet,
wenn eine vorbestimmte Informationseinheit, die im zweiten Zeitentschachteler (33B)
verarbeitet werden soll, vorhanden ist, wenn zwei oder mehrere vorbestimmte Informationseinheiten
vorhanden sind, die von einem vorbestimmten Rahmen im zweiten Zeitentschachteler (33B)
zu verarbeiten sind, und dann der Steuerungsteil (51) die Ausgabe erneut vom ersten
Zeitentschachteler (33A) auf den zweiten Zeitentschachteler (33B) nach der wiederaufgenommenen
Ausgabe der Information umschaltet.
6. DVB-T2-Empfänger (1) nach Anspruch 4, worin der Steuerungsteil (51) die Ausgabe vom
zweiten Zeitentschachteler (33B) auf den ersten Zeitentschachteler (33A) umschaltet,
wenn die Ausgabe aller Informationseinheiten, die vom zweiten Zeitentschachteler (33B)
verarbeitet werden, vollständig ist, wenn zwei oder mehrere vorbestimmte Informationseinheiten,
die von einem vorbestimmten Rahmen im zweiten Zeitentschachteler (33B) verarbeitet
werden, vorhanden sind.
7. DVB-T2 Empfänger (1) nach einem der Ansprüche 1 bis 6 ferner umfassend:
Fehlerkorrekturmittel (23) zum Durchführen einer Fehlerkorrektur an der Ausgabe entweder
des ersten oder zweiten Zeitentschachtelers (33A oder 33B).
8. Empfangsverfahren für einen DVB-T2-Empfänger (1), wobei der DVB-T2-Empfänger (1) Empfangsmittel
(11), erste und zweite Zeitentschachteler (33A und 33B), ein Steuerungsteil (51),
Fehlerkorrekturmittel (23) und einen Speicher (52) aufweist, wobei das Empfangsverfahren
die folgenden Schritte umfasst:
Empfangen eines durch Modulieren einer gemeinsamen Paketfolge und Datenpaketfolge
erhaltenen orthogonalen Frequenzmultiplexsignals durch die Empfangsmittel (11), wobei
die gemeinsame Paketfolge aus Paketen besteht, die einer Vielzahl von Strömen gemeinsam
sind, und wobei die Datenpaketfolge aus Paketen besteht, die für einen der Vielzahl
von Strömen spezifisch sind, wobei die Vielzahl von Strömen Physical Layer Pipes (PLPs)
und die gemeinsame Paketfolge ein gemeinsames PLP und die Datenpaketfolge ein Daten-PLP
ist;
Sortieren der gemeinsamen Paketfolge, die durch Demodulieren des empfangenen orthogonalen
Frequenzmultiplex-Signals im Zeitbereich durch den ersten Zeitentschachteler (33A)
erhalten wird, und
Sortieren der Datenpaketfolge, die durch Demodulieren des empfangenen orthogonalen
Frequenzmultiplexsignals im Zeitbereich durch den zweiten Zeitentschachteler (33B)
erhalten wird;
Umschalten der Ausgabe an die Fehlerkorrekturmittel (23) zum Behandeln der Fehlerkorrektur
vom ersten Zeitentschachteler (33A) zum zweiten Zeitentschachteler (33B), durch den
Steuerungsteil (51), wenn, während der erste Zeitentschachteler (33A) seine Ausgabe
an die Fehlerkorrekturmittel (23) liefert, der zweite Zeitentschachteler (33B) sein
Schreiben einer vorbestimmten Informationseinheit beendet, die zum Speicher (52) zu
verarbeiten ist, und Informationen speichert, die zum Fortsetzen der Ausgabe des ersten
Zeitentschachtelers (33A) erforderlich sind.
9. Empfangsverfahren nach Anspruch 8, ferner umfassend:
Umschalten der Ausgabe vom ersten Zeitentschachteler (33A) auf den zweiten Zeitentschachteler
(33B) durch den Steuerungsteil (51), wenn die Eingabe der ersten vorbestimmten Informationseinheit,
die verarbeitet werden soll, abgeschlossen ist, wenn zwei oder mehrere vorbestimmte
Informationseinheiten vorhanden sind, die von einem vorbestimmten Rahmen in den anderen
Sortiermitteln zu verarbeiten sind.
10. Empfangsverfahren nach Anspruch 8 oder 9, ferner umfassend:
Umschalten der Ausgabe an die Fehlerkorrekturmittel vom zweiten Zeitentschachteler
(33B) zum ersten Zeitentschachteler (33A) durch den Steuerungsteil (51), wenn die
Ausgabe der vorbestimmten Informationseinheit, die vom zweiten Zeitentschachteler
(33B) verarbeitet wird, abgeschlossen ist.
11. Empfangsverfahren nach Anspruch 8, 9 oder 10, ferner umfassend:
Steuern der Ausgabe des ersten Zeitentschachtelers (33A) durch den Steuerungsteil
(51), so dass die Ausgabe des ersten Zeitentschachtelers (33A), auf den die Ausgabe
umgeschaltet wurde, vom Beginn der vorbestimmten Einheit an fortgesetzt wird, die
unvollständig beendet wurde.
12. Umschalten der Ausgabe vom zweiten Zeitentschachteler (33B) auf den ersten Zeitentschachteler
(33A) durch den Steuerungsteil (51), wenn im zweiten Zeitentschachteler (33B) eine
vorbestimmte Informationseinheit verarbeitet werden soll, die im zweiten Zeitentschachteler
(33B) verbleibt, wenn zwei oder mehrere vorbestimmte Informationseinheiten vorhanden
sind, die im zweiten Zeitentschachteler (33B) von einem vorbestimmten Rahmen zu verarbeiten
sind, und dann erneut umschalten, durch das Steuerungsteil (51), der Ausgabe vom ersten
Zeitentschachteler (33A) auf den zweiten Zeitentschachteler (33B), nachdem die erneute
Ausgabe von Informationen durch den ersten Zeitentschachteler (33A) abgeschlossen
ist.
13. Empfangsverfahren nach Anspruch 11, ferner umfassend:
Umschalten der Ausgabe vom zweiten Zeitentschachteler (33B) auf den ersten Zeitentschachteler
(33A) durch den Steuerungsteil (51, wenn die Ausgabe aller vom zweiten Zeitentschachteler
(33B) verarbeiteten Informationseinheiten abgeschlossen ist, wenn zwei oder mehrere
vorbestimmte Informationseinheiten eines vorbestimmten Rahmens im zweiten Zeitentschachteler
(33B) verarbeitet werden.
14. Empfangsverfahren nach einem der Ansprüche 8-13, ferner umfassend:
Durchführen einer Fehlerkorrektur an der Ausgabe entweder des ersten oder des zweiten
Zeitentschachtelers (33A oder 33B) mithilfe der Fehlerkorrekturmittel (23).
15. Ein Programm für einen Computer, das, wenn es in den Computer geladen wird, so angepasst
ist, dass es die Schritte des Empfangsverfahrens nach einem der Ansprüche Anspruch
8-14 ausführt.
1. Récepteur DVB-T2 (1) comprenant :
un moyen de réception (11) pour recevoir un signal de multiplexage par répartition
en fréquences orthogonales obtenu par modulation d'une séquence de paquets communs
et d'une séquence de paquets de données, la séquence de paquets communs étant constituée
de paquets communs à une pluralité de flux et la séquence de paquets de données étant
constituée de paquets spécifiques à l'un de la pluralité de flux, la pluralité de
flux étant des PLP (Physical Layer Pipes), la séquence de paquets communs étant un
PLP commun et la séquence de paquets de données étant un PLP de données, un moyen
de correction des erreurs (23) et
un désentrelaceur temporel (33) comprenant :
un premier désentrelaceur temporel (33A) pour trier la séquence de paquets communs,
obtenue par démodulation du signal de multiplexage par répartition en fréquences orthogonales,
dans le domaine temporel ; et
un deuxième désentrelaceur temporel (33B) pour trier la séquence de paquets de données,
obtenue par démodulation du signal de multiplexage par répartition en fréquences orthogonales,
dans le domaine temporel ;
une mémoire (52) ;
une pièce de contrôle (51) pour transférer la sortie transmise au moyen de correction
des erreurs (23) pour la gestion de la correction des erreurs du premier désentrelaceur
temporel (33A) au deuxième désentrelaceur temporel (33B) si, pendant que le premier
désentrelaceur temporel (33A) transmet sa sortie au moyen de correction des erreurs
(23), le deuxième désentrelaceur temporel (33B) termine l'écriture d'une unité d'informations
prédéterminée à traiter dans la mémoire (52) et pour stocker les informations requises
pour reprendre la sortie du premier désentrelaceur temporel (33A).
2. Récepteur DVB-T2 (1) selon la revendication 1, dans lequel :
la pièce de contrôle (51) transfère la sortie du premier désentrelaceur temporel (33A)
au deuxième désentrelaceur temporel (33B) lorsque l'entrée de la première unité d'informations
prédéterminée à traiter est complète s'il existe deux unités d'informations prédéterminées
à traiter ou plus d'une trame prédéterminée dans l'autre moyen de tri.
3. Récepteur DVB-T2 (1) selon la revendication 1 ou 2, dans lequel la pièce de contrôle
(51) transfère la sortie transmise au moyen de correction des erreurs du deuxième
désentrelaceur temporel (33B) au premier désentrelaceur temporel (33A) lorsque la
sortie de l'unité d'informations prédéterminée traitée du deuxième désentrelaceur
temporel (33B) est complète.
4. Récepteur DVB-T2 (1) selon la revendication 1, 2 ou 3, dans lequel :
ladite pièce de contrôle (51) est en outre adaptée pour contrôler la sortie du premier
désentrelaceur temporel (33A) de sorte que la sortie du premier désentrelaceur temporel
(33A), auquel la sortie a été transmise, reprenne à partir du début de l'unité prédéterminée
qui s'est terminée de manière incomplète.
5. Récepteur DVB-T2 (1) selon la revendication 4, dans lequel la pièce de contrôle (51)
transfère la sortie du deuxième désentrelaceur temporel (33B) au premier désentrelaceur
temporel (33B) lorsqu'il reste une unité d'informations prédéterminée à traiter dans
le deuxième désentrelaceur temporel (33B) s'il existe deux unités d'informations prédéterminées
à traiter ou plus d'une trame prédéterminée dans le deuxième désentrelaceur temporel
(33B), et
la pièce de contrôle (51) transfère ensuite à nouveau la sortie du premier désentrelaceur
temporel (33A) au deuxième désentrelaceur temporel (33B) lorsque la reprise de la
sortie d'informations par le premier désentrelaceur temporel (33A) est complète.
6. Récepteur DVB-T2 (1) selon la revendication 4, dans lequel la pièce de contrôle (51)
transfère la sortie du deuxième désentrelaceur temporel (33B) au premier désentrelaceur
temporel (33A) lorsque la sortie de toutes les unités d'informations traitées du deuxième
désentrelaceur temporel (33B) est complète s'il existe deux unités d'informations
prédéterminées traitées ou plus d'une trame prédéterminée dans le deuxième désentrelaceur
temporel (33B).
7. Récepteur DVB-T2 (1) selon l'une des revendications 1 à 6, comprenant en outre :
un moyen de correction des erreurs (23) pour exécuter une correction des erreurs sur
la sortie du premier ou du deuxième désentrelaceur temporel (33A ou 33B).
8. Moyen de réception pour un récepteur DVB-T2 (1), le récepteur DVB-T2 (1) possédant
un moyen de réception (11), un premier et un deuxième désentrelaceurs temporels (33A
et 33B), une pièce de contrôle (51), un moyen de correction des erreurs (23) et une
mémoire (52), le procédé de réception comprenant les étapes suivantes :
réception, par le moyen de réception (11), d'un signal de multiplexage par répartition
en fréquences orthogonales obtenu par modulation d'une séquence de paquets communs
et d'une séquence de paquets de données, la séquence de paquets communs étant constituée
de paquets communs à une pluralité de flux et la séquence de paquets de données étant
constituée de paquets spécifiques à l'un de la pluralité de flux, la pluralité de
flux étant des PLP (Physical Layer Pipes), la séquence de paquets communs étant un
PLP commun et la séquence de paquets de données étant un PLP de données ;
tri, par le premier désentrelaceur temporel (33A), de la séquence de paquets communs,
obtenue par démodulation du signal de multiplexage par répartition en fréquences orthogonales,
dans le domaine temporel ; et
tri, par le deuxième désentrelaceur temporel (33B), de la séquence de paquets de données,
obtenue par démodulation du signal de multiplexage par répartition en fréquences orthogonales,
dans le domaine temporel ;
transfert, par la pièce de contrôle (51), de la sortie transmise au moyen de correction
des erreurs (23) pour la gestion de la correction des erreurs du premier désentrelaceur
temporel (33A) au deuxième désentrelaceur temporel (33B) si, pendant que le premier
désentrelaceur temporel (33A) transmet sa sortie au moyen de correction des erreurs
(23), le deuxième désentrelaceur temporel (33B) termine l'écriture d'une unité d'informations
prédéterminée à traiter dans la mémoire (52) et pour le stockage des informations
requises pour reprendre la sortie du premier désentrelaceur temporel (33A).
9. Procédé de réception selon la revendication 8, comprenant en outre :
le transfert, par la pièce de contrôle (51), de la sortie du premier désentrelaceur
temporel (33A) au deuxième désentrelaceur temporel (33B) lorsque l'entrée de la première
unité d'informations prédéterminée à traiter est complète s'il existe deux unités
d'informations prédéterminées à traiter ou plus d'une trame prédéterminée dans l'autre
moyen de tri.
10. Procédé de réception selon la revendication 8 ou 9, comprenant en outre :
le transfert, par la pièce de contrôle (51), de la sortie transmise au moyen de correction
des erreurs du deuxième désentrelaceur temporel (33B) au premier désentrelaceur temporel
(33A) lorsque la sortie de l'unité d'informations prédéterminée traitée du deuxième
désentrelaceur temporel (33B) est complète.
11. Procédé de réception selon l'une des revendications 8, 9 ou 10, comprenant en outre
:
le contrôle, par ladite pièce de contrôle (51), de la sortie du premier désentrelaceur
temporel (33A) de sorte que la sortie du premier désentrelaceur temporel (33A), auquel
la sortie a été transférée, reprenne à partir du début de l'unité prédéterminée qui
s'est terminée de manière incomplète.
12. Procédé de réception selon la revendication 11, comprenant en outre :
le transfert, par la pièce de contrôle (51), de la sortie du deuxième désentrelaceur
temporel (33B) au premier désentrelaceur temporel (33B) lorsqu'il reste une unité
d'informations prédéterminée à traiter dans le deuxième désentrelaceur temporel (33B)
s'il existe deux unités d'informations prédéterminées à traiter ou plus d'une trame
prédéterminée dans le deuxième désentrelaceur (33B), et
un nouveau transfert, par la pièce de contrôle (51), de la sortie du premier désentrelaceur
temporel (33A) au deuxième désentrelaceur temporel (33B) lorsque la reprise de la
sortie d'informations par le premier désentrelaceur temporel (33A) est complète.
13. Procédé de réception selon la revendication 11, comprenant en outre :
le transfert, par la pièce de contrôle (51), de la sortie du deuxième désentrelaceur
temporel (33B) au premier désentrelaceur temporel (33A) lorsque la sortie de toutes
les unités d'informations traitées du deuxième désentrelaceur temporel (33B) est complète
s'il existe deux unités d'informations prédéterminées traitées ou plus d'une trame
prédéterminée dans le deuxième désentrelaceur temporel (33B).
14. Procédé de réception selon l'une des revendications 8 à 13, comprenant en outre :
l'exécution d'une correction des erreurs par le moyen de correction des erreurs (23)
sur la sortie du premier ou du deuxième désentrelaceur temporel (33A ou 33B).
15. Programme informatique qui, lorsqu'il est chargé sur l'ordinateur, est adapté pour
exécuter les étapes du procédé de réception selon l'une des revendications 8 à 14.